In the prior art, a variety of devices for compressing bone have been known. See, for example, U.S. Pat. No. 4,456,005, U.S. Pat. No. 4,688,561, U.S. Pat. No. 4,796,612 and U.S. Pat. No. 5,217,462. In U.S. Pat. No. 5,167,664 a ratcheting bone screw is disclosed.
It is an object of this invention to provide another compression device which is very strong, which can be customized in length, which can be retightened periodically to maintain compression, which allows precise placement and alignment of bones with both grossly tuned compression and finely tuned compression, and in which only a limited inventory of parts is required.